Beans: A Healthy Dietary Vegetable

12/04/2019

Bean is a common name
applied to large seeds of several genera of family Fabaceae used for human as
well as animal consumption. The green, young pods of bean plants are often
consumed as raw or cooked. They are known as green beans when unripe. The term bean
is generally used for the broad bean but later on it was expanded to include
members belonging to the genus Phaseolus as well as Vigna. The term is now
applied to many other plants also for example soybeans, peas, lentils,
chickpeas (garbanzos), vetches, and lupins.

Beans are one of the
oldest plants known in cultivation since times immemorial. Broad beans were
earlier cultivated in Afghanistan and Himalayan foothills. Common bean is known
in cultivation for about six thousand years in America. About 4,000 cultivated
varieties are known from America alone. The common varieties of bean include
broad bean, moth bean, urad bean, mung bean, rice bean and cowpea. Some
varieties of bean especially the red and kidney beans contain a toxin that must
be destroyed before cooking.

The recommended method
adopted for these beans is to boil them for ten minutes as the undercooked
beans are more harmful than the raw ones. Fermentation is often employed in
many parts of Africa as it improves the nutritional value of beans by removing
toxins. Inexpensive fermentation improves the nutritional value of the flour of
beans and hence enhances digestibility as shown in a study carried out at Addis
Ababa University. They are a major source of protein in Kenya, Malawi,
Tanzania, Uganda and Zambia.

They contain
significant amounts of fiber and soluble fiber. One cup of cooked beans
provides about 9-13 grams of fiber. Soluble fiber helps to lower the
cholesterol level. They also contain high levels of protein, complex
carbohydrates, folate, and iron. Many edible beans especially the broad beans
and the soy beans contain oligosaccharides which is a type of a sugar molecule
as found in cabbage. An anti-oligosaccharide enzyme is required to digest these
sugar molecules. The human digestive system lacks any anti-oligosaccharide
enzyme these sugar molecules are particularly broken down by the bacteria
present in the large intestine.

These sugars upon
digestion produce flatulence-causing gases as a byproduct. Some species of
molds produce alpha-galactosidase, an anti-oligosaccharide enzyme which
facilitate the digestion of these oligosaccharide molecules more effectively in
the small intestine if consumed by humans. These enzymes are sold in the
markets under the trade name Beano in the United States. Beans can be cooked
with natural carminatives like anise seeds, coriander seeds and cumin. They are
also soaked in water and the vinegar is added to them. Brazil is the largest
producer of beans followed by India and China.